Air and water tight butt seam or joint



(No Model.)

' T G. J. TAGG.

4 'AIR AND WATER TIGHT BUTT SBAM 0R JOINT. No. 339,710.

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UNITED STATE PATENT @rrrcs.

GEORGE JOHN TAGG, OF EAST MOULSEY, COUNTY OF SURREY, ENGLAND.

AIR AND WATER TIGHT BUTT SEAM OR JOINT.

SPECIFICATION forming part of Letters Patent No. 339,710, dated Apr-i113, 1886.

Application filed October 27, ISPS. Serial No. 181,079.. (No model.) Patented in Englmd October 27, 1881, No. 1 lfll-J.

To all whom it may concern:

Be it known that I, GEORGE JOHN TAGG, of the firm of T. G. Tagg 8t Son, a subject of the Queen of Great Britain, residing at East Moulsey, in the county of Surrey, England,

wood-work where it is necessary to make a.

butt-j oint between two planks or boards which shall be capable of successfully resisting the influence of damp or heat, or of any atmospheric change capable of producing a contraction or an expansion of said joint likely to wear or break it.

It is a well-known fact that when two boards are laid edge to edge-e. 9., in the case of a ships deck, or of the floor of a room or a veranda, or of a boarded partition or wall of a cabina rise in temperature will dry up the boards, thereby contracting them and causing the joints to open, and that during a subsequent term of wet weather the boards will not only swell out again sufficiently to make the joints tight, but may expand to a sufficient extent to make them partially drag themselves away from the nails or screws used to fasten them to the cross beams or joists or the like.

In boat -building it has always been the practice to make the seams permanently tight by means of calking them with tow or similar fiber; but the elasticity of these calked joints has constantly shown itself as quite unequal to bearing the strains of expansion and contraction to which the boards have been subjected. The edges of the boards, too, suffer considerable injury from the blows delivered upon the calking-tool, and damp easily finds a lodgment in the calking material, either at the time of making the seam or shortly after; besides this, a seam made in this way is always more or less unsightly.

The experience of calked seams, as practiced in boat-building,has been repeated whenever a butt-joint calked in the same way as the seams of a boat has been exposed to considerable atmospheric changes. This being the case, it is evident that for the production of a perfect buttjoint in constructional woodwork it is essential to employ a material that will not be deleteriously affectedmuch less destroyed-by the maximum compression to which it may be subjected by the expansion of the boards between which it is laid,and still be endowed with sullicient natural elasticity to follow the separating edges of the boards as the latter contract under the influence of 6 heat,without either being torn or cracked or wrenched away from its hold on the edges of the boards.

The accompanying figures illustrate the application of my invention to making a joint 7 between the edges of two long boards of the same thickness laid edge to edge, although I would have it distinctly understood that my improved joint may be advantageously used in constructional wood-work whenever it is 7 required to make a buttjoint capable of resisting the influences of considerable atmospheric changes, and is not limited by the relative dimensions of the adjoining pieces or their ultimate position and use. Forinstance, it is applicable in boat-building for the hull and deck seams, for the floors of verandas, and other open-aired lloored spaces, for walls and partitions of wooden buildings, and for certain domestic work, as parquet flooring.

Figure 1 is a sectional elevation. Fig. 2 is a plan, and Fig. 3 is a section ol a scam orjoint on a larger scale.

The edges of the boards. or pieces are left tolerably true, but not necessarily finished with exact truth. This inequality of surface enables the edges of the boards to gain and keep a better hold upon the material I use for making my improved joint. The material I use is coarse linen, canvas, or the like, in strips in width about equal to the width of the edges of the boards or pieces to be joined and of the length of the seam. These strips a are single, double, or manifold, as the thickness of the boards and length of the joint, as well as the degree of elasticity'required therein, may render advisable. lVhen used double, the fold b is always underneath or on the inside, the two edges 0 c of the material projecting upward or joists in the ordinary way.

In consequence of the natural elasticity of the canvas, which is increased by the soaking before described, and the adhesive properties of the copal-varnish a perfectly air-tight as well as water-tight seam is produced without delivering a single blow upon the boards, or in any way exerting any pressure upon them capable of crushing or distorting their fibers.

My improvedjoint is from the durable and elastic nature of the materials employed unaffected by changes of temperature and climate.

The protruding edges of the canvas areshaved off, leaving the general surface smooth and the 25 seams sightly. Any further protrusion due to swelling of the material under the influence of moisture will manifest itself on the under or inner side of the joint, where the fold b is.

Thus by placing the fold under or inside, as 0 illustrated, due provision is made for sion without unsightliness.

I claim In making an air and water tight joint beprotrutween two boards or pieces of wood in con- 55 structional wood-work, the combination of a single or multiple fold of canvas or similar material previously saturated in copal-Varnish .with the said two boards or pieces of wood,

the whole substantially as described with ref- 40 erence to the accompanying drawings.v

In testimony whereof I hereunto sign my name, in the presence of two subscribing witnesses, this 22d day of July, 1885.

GEORGE JOHN TAGG. \Vitnesses:

R. A. BLAKE, J. G. FRANK. 

